Wet or dry sump motor

ABSTRACT

A compressed air motor having an interchangeable rotary valve cap to enable the motor to be operated selectively with a wet or dry sump depending on whether the usage is required on a horizontal axis or an axis deviating from the horizontal.

United States Patent 1 11 3,808,808 I Hibbard 5] May 7, 1974 1 WET OR DRY SUMP MOTOR 3,513,657 5/1970 Nelson 60/57 R [76] Inventor: George A. Hibbard, River Rd" 3,023,738 3/1962 Burgess 60/370 03743 FOREIGN PATENTS OR APPLICATIONS 1 Flledl 24, 1973 640,120 3/1928 France 60/412 21 Appl. No.2 326,350

Related U.S. Application Data Primary ExaminerEdgar W. Geoghegan [63] Continuation of Ser. No. 195,233, Nov. 3, 1971,

abandoned.

' [57] ABSTRACT [52] U.S. Cl 60/327, 60/370, 60/456 [51] Int. Cl. FlSb 11/06 I A compressed air motor having an interchangeable 58 Field of Search 60/327, 369, 370, 378, my valve cap to enable the motor to be operated 60/453, 455, 456; 91/340, 352; 92/153, 154 lectively with a wet or dry sump depending on whether the usage is required on a horizontal axis or [56] References cued an axis deviating from the horizontal.

UNITED STATES PATENTS 3,398,533 8/1968 Wolfbauer 60/57 R Claims, 6 Drawing Figures 2a L n 58 22k 60- /2 3o 54 s 1 F 4a WET R DRY SUMP MOTOR This is a continuation, of application Ser. No. 195,233, filed Nov. 3, l97l now abandoned.

BACKGROUND OF INVENTION A normal compressed gas motor mounting is on a horizontal axis with the individual cylinders operating in a vertical plane about a rotating horizontal shaft. Associated therewith is a valve rotatable in a horizontal axis responsively to crank shaft rotation to permit a timed inlet of compressed gas such as air and a timed exhaust of the expanded air after utilization in the power stroke of the motor. Lubrication of this type of motor is normally of the wet sump type having a crankcase containing oil, which is pumped by separate pumps or splashed by motor action to coat the various bushing, bearings and moving elements. The wet sump type of lubrication is generally utilized when the motor .is operated with the output shaft on a horizontal or near-horizontal axis to prevent the liquid lubricating oil from spilling out the motor housing breather ports, and also prevent the oil from leaking into the expansion chamber and hindering the motor action. If it is necessary to operate out of the horizontal axis, a completely different air motor must be utilized wherein liquid lubrication is not required. The different type motor is a so-called dry sump motor wherein lubrication is provided by injecting oil into the intake compressed air stream external to the motor by use of a line oiler to provide an oil mist which is circulated through the internal motor housing for necessary lubrication.

SUMMARY OF INVENTION According to the present invention, there is provided a new and novel interchangeable valve cover means for use with air motors having venting at the end of a rotary valve, said valve cover means enabling interconversion from wet sump lubrication to dry sump lubrication as desired while utilizing a single air motor.

Other provisions of the present invention will become more apparent when taken in conjunction with the accompanying detailed description and the drawings wherein:

. FIG. 1 is an outline view of an air motor partly in section with an end vented rotary valve;

FIG. 2 is an outlineend view of the air motor with an open end valve cover in position;

- FIGS. 3 and 4 are respective side and front elevational views of a closed end valve cover; and

FIGS. 5 and 6' are respective side and front elevational views of an open end valve cover.

Referring to FIG. 1, there is shown a compressed gas motor, the gas for example being compressed air such that the motor hereinafter is referred to as an air motor 10. The air motor 10 includes the usual radial motor housing 12 containing a rotatable crankshaft 14, the outward extending end of which is the motor output drive shaft 16. The crankshaft 14 is fonned with the usual single crank throw 18 having a master bearing 20 manner as can be seen in FIG. 2 where five such assemblies are housed. A rotary valve 32 is suitably secured to the inside end 34 of the crankshaft 14 to be rotated in a valve housing 36 to provide the usual timed inlet and exhaust valving operations for a motor of this type. The rotary valve 32 is of the open-ended type where the exhaust passage 38 opens to the outer end 40 of the rotary valve 32 while the inlet passage 42 is on the circumferential surface to be in communication with an intake port 44 circularly grooved within the inside surface 42 of the valve housing 36. Lubrication of the motor 10 is provided for the usual bearings ,48 on the crankshaft, master bearing 20 on the crank throw 18, and rings 50 and 52 encircling the pistons 26 as further described hereinafter.

A dual purpose passage 54 is suitably formed in the motor housing 12 and the cylinder heads 56 to provide means for intake of compressed air and exhaust of expanded air during the usual well known operation of the air motor. A vent passage 58 is suitably formed in the motor housing 12 to connect the sump-side chamber 60 within the walls 28 of the cylinder 30 and sump 62 below the piston. 26 to a passage 64 in the valve housing 36 to a chamber 66 formed by the end of the valve housing 36, the outer end 40 of the rotaryvalve 32 and valve cover 68. The valve cover 68 may be of one of two types, one type'being the open end valve cover 70 shown in solid line in FIG. 1 and more detailed in FIG. 5 and FIG. 6 with a vent port 72 leading to atmosphere.

The other type valve cover 68 is the closed-end valve cover 74 shown partly in dottedlines in FIG. 1 and in detail in FIGS. 3 and 4 where the chamber 66 is not open to atmosphere but is connected only to passage 64 in the valve housing 36 and the exhaustpassage 38 in the rotary valve 32. The choice of which type of valve cover 68 to be used is dependent on the selection of whether the method of operation of the air motor 10 is to be 0 wet sump operation or dry sump operation as explained hereinafter.

OPERATION In operation, with the piston assembly of the air motor positioned as shown in FIG. I, compressed air is supplied from a suitable source 76 via a conduit means such as a pipe 78 to the intake port 44 in the valve housing 36 and according to the rotative position of the rotary valve 32, (shown in FlG.,l as in an intake position), the compressed air is rapidly supplied through the inlet passage 42 in the rotary valve 32 to the passage 54 in both the motor housing 12 and thecylinder head 56 to a usual expansion chamber 80 above the piston 26 wherein the compressed air supplied thereto is rapidly expanded to move the piston 26 downward to provide the usual power stroke to the piston assembly and rotate the crankshaft 14 in a normal driving manner. The air motor operates in a normal two-stroke cycle such that the rotary valve 32 is rotated with the rotating crankshaft 14 to thereby connect the chamber 80 and connected passage 54 to the exhaust passage 38 of rotary valve 32 as the piston 26 and connected assembly moves upward (as viewed in FIG. 1) in its usual exhaust stroke. The type of operation in which the motor 10 is used, determines whether the exhaust passage 38 is vented to atmosphere via chamber 66 and port 72, or recycled from chamber 66 to passage 64, vent passage 58 and sump-side chamber 60 as explained hereinafter. Vent passage 58 leading from the inside of cylinder walls 28 at the sump-side chamber 60 and passage 64 are in communication with chamber 66 within the valve cover 68.

If the lubrication and operation of the air motor is to be of wet sump type, the sump 62 is filled to a preset level with a liquid lubrication as oil via a normally closed filler plug 82. The oil level is preset below the upward extending elongated walls 28 of the lowermost piston assemblies (not shown) to prevent flooding thereof. A normally closed drain plug 84 is provided in the sump 62 for draining when desired. The actual lubrication is accomplished in a well known manner by one or more rotating impellers 86 splashing through the oil in the sump 62 to suitably splash oil to the variously described bearings. During wet sump operation leakage of compressed air past the piston rings 50 and 52 would tend to build up aback pressure in the sump-side chamber 60 but is prevented from doing so by the vent passage 58, passage 64 leading to the chamber 66 where with the open end vent cover 70 utilized in wet sump operation, (shown solid in FIG. 1 and FIGS. 5 and 6), both the chamber 66 and the exhaust passage 38 are vented to atmosphere via vent port 72.

Conversion of the just described air motor from wet sump operation to a dry sump operation is accomplished in three novel steps. The first conversion step is preparing the sump 62 by draining the lubricating oil therefrom at drain plug 84 and replacing the filler plug 82 with a vent fixture 88 such as an open end street elbow (shown partially as dotted in FIG. 1). The second conversion step is replacing the open end valve cover 70 of FIGS. 5 and 6 with the closed end valve 74 of FIGS. 3 and 4 to eliminate the vent port 72 as shown dotted at 74 in FIG. 1 thereby connecting the exhaust passage 38 and chamber 66 to passage 64 of the valve housing 36. The third conversion step is to open the normally closed cut-off valve 90 which permits a well known type of line oiler 92 to supply lubricating oil into the compressed air stream passing through pipe 78 to effect a delivery of a mixture of compressed air and a lubricating oil mist at the inlet port 44.

The operation of the piston assembly of the air motor with ,dry sump is similar to that described with wet sump however lubrication is accomplished in a different manner explained as follows:

In the intake and expansion stroke of the piston 26 the mixture of compressed air and oil mist is delivered from the intake port 44 through passage 42 in the rotary valve 32 and passage 54 to the expansion chamber 80 above the piston 26 where the compressed air expands to move the piston 26 downward in a usual driving manner. On the upward or exhaust stroke, the expanded air and oil mist while lubricating the piston walls 28 at the rings 50 and 52 is pumped back out of the chamber 80 via passage 54 to the exhaust passage 38 of rotary valve 32 which has now rotated in normal manner such that passages 54 and 38 are in communication with each other. Due to the closed end valve cover 74 the exhaust passage is not able to vent to atmosphere, but the oil mist therein is forced back through chamber 66 therein to passage 64 in the valve housing 36 to vent passage 58 and into the interior of the extended end of the elongated piston walls 28 and the sump-side chamber 60 which is now of increased volume due to the lack of liquid in the sump 62. It can thus be seen that this oil mist being reversed circulated through a normal venting passage 58 will readily build up a heavy lubricating mist in the interior of the motor said fixture. With no liquid oil in the motor housing, the

motor can now be operated out of a horizontal plane in any position to or attitude and still be well lubricated by the internal oil mist.

Conversion from dry sump to wet sump is readily accomplished by reversing the previously described conversion steps by closing cut-ofi valve 90 to prevent delivery of oil from the linefoiler 92, changing the closed end valve cover 74 to an open end line cover 70, and filling the sump 62 and replacing the closed filler plug 82.

It can thus be seen that the use of a single air motor in any mounting position can be attained by this new and novel method of interchange of lubricating means from wet sump" to dry sump and vice versa.

Since'various changes may be made in the abovedescribed construction with different passage and port arrangements and different embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all matter contained in the foregoing description as shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. i

What is claimed is: V

l. [n a compressed air operated motor of the wet sump type having a rotary valve with an exhaust port the method of preparing such a motor for dry sump operation, comprising the steps of; removing the liquid lubricant from the sump of said motor, providing means for supplying vaporized oil lubricant to the compressed air intake of said motor, eliminating direct communication of said exhaust port with the atmosphere, providing means for circulating the vaporized,

oil via said exhaust port and other passages to the internal portion of said motor including said sump, and opening a passage from said sump to the atmosphere.

2. The method as set forth in claim 1 wherein the step of closing the communication of exhaust passages to atmosphere includes replacing an open end rotary valve cover with a closed end rotary valve cover.

3. The method as set forth in claim 2 further characterized by establishing a circulating communication through said closed end rotary valve cover.

4. In the method as specified in claim 1 the additional steps of disconnecting said means for supplying vaporized oil, reestablishing said direct communication of said exhaust port with the atmosphere, refilling said sump with lubricant and closing said passage from said sump to said atmosphere to return said motor to wet sump operating condition.

5. The method as set forth in claim 1 further including the step of establishing a vapor circulating passage through said exhaust passages and an internal vent passage.

6. A compressed air operated motor having a sump, a rotary valve with exhaust means communicating directly with the atmosphere during wet sump operation,

and having selectively usable means utilized only for dry sump operation comprising: one of said selectively usable means for eliminating said communicating directly with the atmosphere of said exhaust means, other of said selectively usable means for supplying vaporized oil lubricant to an intake passage of said motor, and still other of said selectively usable means communicating said exhaust means through said sump to the atmosphere.

7. The communication set forth in claim 6 further characterized by including a sump ventilating means when vaporized oil is supplied therein.

8. The combination set forth in claim 6 further including a source of supply of vaporized oil to said sump when no liquid oil is present therein.

with the atmosphere. 

1. In a compressed air operated motor of the wet sump type having a rotary valve with an exhaust port, the method of preparing such a motor for dry sump operation, comprising the steps of; removing the liquid lubricant from the sump of said motor, providing means for supplying vaporized oil lubricant to the compressed air intake of said motor, eliminating direct communication of said exhaust port with the atmosphere, providing means for circulating the vaporized oil via said exhaust port and other passages to the internal portion of said motor including said sump, and opening a passage from said sump to the atmosphere.
 2. The method as set forth in claim 1 wherein the step of closing the communication of exhaust passages to atmosphere includes replacing an open end rotary valve cover with a closed end rotary valve cover.
 3. The method as set forth in claim 2 further characterized by establishing a circulating communication through said closed end rotary valve cover.
 4. In the method as specified in claim 1 the additional steps of disconnecting said means for supplying vaporized oil, reestablishing said direct communication of said exhaust port with the atmosphere, refilling said sump with lubricant and closing said passage from said sump to said atmosphere to return said motor to wet sump operating condition.
 5. The method as set forth in claim 1 further including the step of establishing a vapor circulating passage through said exhaust passages and an internal vent passage.
 6. A compressed air operated motor having a sump, a rotary valve with exhaust means communicating directly with the atmosphere during wet sump operation, and having selectively usable means utilized only for dry sump operation comprising: one of said selectively usable means for eliminating said communicating directly with the atmosphere of said exhaust means, other of said selectively usable means for supplying vaporized oil lubricant to an intake passage of said motor, and still other of said selectively usable means communicating said exhaust means through said sump to the atmosphere.
 7. The communication set forth in claim 6 further characterized by including a sump ventilating means when vaporized oil is supplied therein.
 8. The combination set forth in claim 6 further including a source of supply of vaporized oil to said sump when no liquid oil is present therein.
 9. The combination set forth in claim 8 further including a valving means for selectively supplying said vaporized oil to said motor.
 10. A compressed air operated motor having a sump, a rotary valve with exhaust means communicating through said sump with the atmosphere during dry sump operation, and having selectively usable means utilized only for wet sump operation, comprising: one of said selectively usable means for establishing direct communication between said exhaust means and said atmosphere, and other of said selectively usable means for eliminating said communicating through said sump with the atmosphere. 